I finished testing a newly built Octocopter today and wanted to relay this problem I came across to make the point about there possibly being other issues at play besides the DJI unit being faulty.

On the initial test flight, the aircraft had a tendency to yaw, nose right. I could hold it with a corresponding nose left rudder command, but it was obviously not flying correctly.

I increased the Yaw Gain (I always start at default 100% on all controls), taking it up to 125%.

It helped a little, but it still had a yawing tendency. I increased the gain to 140%. Still there....

The radio being supplied with this aircraft is a Brand New Spektrum DX18. It also has a 5.8 ghz downlink and FPV camera, which was on during these test flights.

After mulling it over for a couple of days, considering possible issues with motors, ESC's, Power distribution, etc, I finally thought that it seemed like there was an actual command to this Yawing movement. I can't explain it, but it simply felt like it was being commanded to yaw, ever so slowly.

Which made me look at the radio, specifically the rudder trim. Moving to the monitor screen, I see the rudder output displaying 0, -1, 0, -1, 0, -1....flashing between the 2 values.

I hooked up the aircraft to the laptop, powered it up and watched the sliders on the Tx calibration screen. Sure enough, the rudder slider was moving ever so slightly, in time with the flashing between the 2 values....

All that was required was to decrease the trim setup settings in the radio, by default at 5, lowering it to 4, eliminating the flashing between the values, eliminating the slider movement, and eliminating the yawing tendency in a subsequent test flight.

The DJI unit was doing exactly as it was being told to do, by the settings in the radio....

My point in relaying this is to not automatically assume a defective autopilot, keep an open mind, consider ALL possibilities including the improbable. I've never seen this issue before, even in other DX18's, and it would have been nigh impossible to troubleshoot over the internet or phone. Knowing your system, your radio, your electronics is paramount to success with any of our flying models, heli's Multi's or fixed wing.

[edit]

Thanks,

Josh MoenTeam Synergy Factory PilotTeam Futaba

Very disappointed with the so called American distributer

The Wookong-m wasn't my only experience with multicopter controllers or DJI products. We had been using the Naza-m with very good luck. I'm very disappointed that the more expensive Wookong-M has so many problems that result in devastating crashes. What's more disappointing is the American distributer instead of correcting or recognizing the problem wants to blame everything on pilot error. All the equipment came from DJI. S-800 and Wookong-m this is supost to be their best. Our intention was to add to the system the zenmuse gimbal and camera. Wow...glad we didn't get that far. After spending three thousand dollars it crashes with in the first six flights. I've been in the helicopter hobby for fifteen years and have experienced my share of problems with equipment failure and pilot error. I know the difference this was a complete lock-out after five other successful flights. The real problem is that the person in charge of American distribution wants to hide the problem. They have no intention in getting to the root of the problem witch means even if I decided to spend another three thousand dollars to replace the system it's still untrustworthy junk. I've been testing R/C helicopters for years and have even offered to travel at my expense to their location to test or repulacate the flight that caused the crash. I believe there is an absolute problem with the system that will occur time after time and if not corrected will cause many to experience great loss.

I have tryed to contact the main DJI distributer in Texas many times only to get a response through E-Mail. Sorry way to do business. It's funny these distributors don't even answer their phones. This has been going on for a mouth and Colin finally sent me an E-Mail saying he was trying to get a conference call going with me and Empire hobbies. Wow... Really???? Still no call.

I'm not sure which one of you spoke to Craig…and if you actually told him "that it was it was obvious the Wookong-M reset and caused the crash", but I'd like to get to the bottom of this. When are you guys available for a conference call with this customer?

Trust me....where did you get that? The fact is that we have sent you the unit to test. What exactly have you done to test the unit we paid to send you at your request or Empire hobbies? It sounds to me that you are asking me to trust you and your limited experience. I did refer to the fact that I have fifteen years of helicopter experience and if challenged would put my flying skills to any test. The things that I know for fact is the problem occurred when the S-800 was in attitude mode. I also know the Wookong went into lock-out or what Empire hobbies called reset. Interesting Empire hobbies even has a name for the problem you say doesn't exist. In fact Empire Hobbies told Mark and I that it was it was obvious the Wookong-M reset and caused the crash. There are others that agree the Wookong-M has problems one of them is Wayne Man team USA pilot. He describes on Runryder how his locked-out. The problem exist.

We have sent the unit to be tested its apparent that you have assumed that we were wrong and refer to sterile test hovering in windless conditions. If you need a test pilot with skills to test these units, I'm available. If you are capable I would like to see the system tested. I can and will arrange to come to your location if necessary.

Please call me. It seems this is an awkward way for DJI to handle problems. A way of hiding behind E-Mails.

Just an FYI, we have 6 teams of guys flying S800's and WKM's on a daily basis shooting everything from Movies & TV shows to Pipeline inspection; and while the WKM definitely has it's flaws (namely dropping in altitude due to excessive vibration) which we are working on, "Locking Up" is not one of them. We have tested more than 10 times 4 S800's flying with WKMs for 72 hours straight (that's three continuous days of hovering) without any "lock ups". Additionally, if there was some kind of malfunction in the autopilot system, you would have heard it in the motors in your GoPro video. And finally, the flight path when watched frame by frame is exactly that of a disorientation.

I would need something more than "trust me, I've been flying for 15 years" to base a warranty replacement decision on. Is that supposed to mean that people who have flown for over "X" number of years don't crash R/C helicopters? That being said, if you had video of a Compass-bug induced fast-flipping crash (which used to happen with the old compass firmware), I would be happy to provide you with a warranty replacement. The number of systems we replaced due to the compass bug (which ZERO other UAV companies would ever do, just call Quadrocopter and ask them what their "warranty" period is for a Cinestar) is more than enough proof to show that I'm not simply trying to "pass the buck" and get out of replacing a system. I hope you can understand that we can't just replace a whole system every time a customer says "trust me, it was the system's fault". We as R/C pilots attempt to defy gravity on a daily basis, and sometime gravity wins. I am very sorry for your loss, and trust me when I say that I can empathize (having lost $100k machines due to mechanical failure), but if a crash like this deters you from participating in this hobby/line-of-work, you may want to look into something that stays on the ground.

Our goal is to make a flying machine that is literally difficult to crash, but until that time, we will all experience crashes from time to time and we must build that into our day rates. In spite of this terrible situation, I hope you have a happy holidays.

The S-800 was in attitude mode during the entire flight. The S-800 went into lock-out or reset and the radio sticks wouldn't respond. I've been flying for fifteen years and can easily recognize a dead stick condition. The Wookong-M was the problem not pilot error. After doing some research this hasn't been the only time this has been reported to you. I was talking to one of your DJI dealers and this has happened to three of his customers and to his own personal machine. He informed you of his problem and you also denied his claim and blamed it on pilot error.

There is a problem with the Wookong-M and it needs to be corrected before there are more crashes.

I saw the video of your crash. The S800 was in manual mode and clearly the aircrafts orientation was lost by the pilot. You would not have been able to fly those helicopter circuits while in Attitude or GPS Attitude mode as you can only pitch the aircraft to 45 degrees in any direction. Next time I would suggest leaving it in Atti or GPS Atti mode during all flights. Sorry for your misfortune Craig.

Colin,
Mark Archigo and I have experienced a problem with the Wookomg-M. Mark had purchased a complete DJI system S-800 and Wookong-M on the sixth flight while in attitude mode the system locked out, the S-800 flew across the field and crashed causing considerable damage. Due to the fact that system caused the problem we believe DJI needs to repair the damage or replace the broken parts. We are also informing you that the Wookong-M has problems. The problem needs to be taken seriously and corrected before there are more accidents.

Thank you,
Craig Courtney
816-728-8757

Sent from my iPhone

Thunderbirds Rock and Roar

Craig,
I saw the video of your crash. The S800 was in manual mode and clearly the aircrafts orientation was lost by the pilot. You would not have been able to fly those helicopter circuits while in Attitude or GPS Attitude mode as you can only pitch the aircraft to 45 degrees in any direction. Next time I would suggest leaving it in Atti or GPS Atti mode during all flights. Sorry for your misfortune Craig.

Colin Guinn
CEO - North America
DJI Innovations
facebook.com/iflydji

BS! I watched the video.

I own both the Naza and WKM. I am 99.999% sure the WKM equipped S-800 was NOT flying in manual mode. Anyone who owns these DJI systems can easily tell it was not manual mode. Manual mode lacks the smoothness you get with ATT and GPS modes. No gimbal can remove the level of instability you get with Manual mode. The GoPro camera used has no stabilization either. Also, the aircraft did not exceed 45° from horizontal until control was lost.

Whether the crash was due to the WKM or some other flight system failure may be debatable, but it certainly did not appear to be caused by loss of orientation pilot error.

I suspect that perhaps an ESC went out. The aircraft tilted and drifted sideways to the left at a rapid rate before rolling and crashing. This indicates a lack of lift of the left side on the aircraft.

I do agree with the OP about the lack of professionalism on the part of Colin Guinn/N.A. DJI Innovations. Telling someone it was pilot error when it clearly isn't is a poor tactic known as blaming the victim. Nothing can be more infuriating to the customer. Sadly, Colin forgot the golden rule of customer service.

Craig,

I'm very sorry that our situation has come to this. Additional, I'll state again that we are very sorry you had the experience you did with Mark's S800.

We all work very long hours to develop the best flying systems we possibly can for customers around the world to enjoy. Are we perfect? Absolutely not...for that, I also apologize. If any of my emails came across terse or rude I'm sorry.

My point was to simply state that I don't see anything in your video to suggest there was a malfunction of the WKM. There are plenty of videos that I've watched where the "FOD" is caused by a compass bug (so ironic since that was a more expensive compass for us and was meant to fix the Southern Hemisphere GPS issue). When I see these videos - every single time - we replace the entire system free of charge. Please tell me if you know another manufacturer of any flying system that would do the same.

It's not about trying to pass the buck to the pilot...and it's not about you or your skills / experience as a pilot. It is a matter of principle that we can not replace every crashed system that a customer claims to be a "DJI Problem".

Finally, I'm sorry that it is difficult for me to get on a 30 minute phone call with every customer that has a problem...this simply would not be a scalable solution and it would delay product development and product launches. Literally, there would not be enough time in the day for me to get anything done. That being said, because you were so unhappy, I was (and still am) willing to get on a conference call with your dealer and you to discuss this issue. I will reach out to them again to see when we can get on a call...if you still want to do that.

I am sorry you have been so unhappy, and I wish I could make it all better...but we simply can't make every single customer happy every single time.

If you are still interested in becoming a dealer, and if that ever happens, you will better understand the process of what we are trying to do to support our customers in the best possible way. Maybe some day we'll have much more positive and productive communication about bringing great products to happy customers. Have a good day Craig.

I have a vast knowledge of DJI products and the WKM. When I watch that first video, all I can see is pilot error / classic disorientation, which is easy with any Hex Copter!
And...I've had no issues with DJI support.
Just my view, for what it's worth.

If I may say something gentlemen?

in Attitude or GPS Attitude mode as you can only pitch the aircraft to 45 degrees in any direction

I've read the thread completely, reviewed the video and the moment preceding loss of control, and believe you should examine minute 5:.

Was the dji attitude mode put to the extreme by a momentary over 45 degree turn, just enough to cause the s-800 to reset? Probable, but not conclusive.

Under all circumstances both parties should divide the responsibility equally, the operator who perhaps tested the system to its limits, and DJI who has something to learn and improve upon for future developments which put their valued customers at ease.

I'm personally working toward a full ap rig but am also redesigning my rc ships with a variety of improvements, as are a handful of individuals world wide.

I would not invest in a system with two different modes such as attitude and or manual modes, but on a system that is a "manual assist mode that like a 3 axis gyro on a typical fbl heli, would stabilize the quad/octo,cetera similarly without lock out issues what-so-ever. For that instance when some s-800 limitation of 45 degrees in attitude is accidentally breeched.

In the name of improving quality of playback DJI takes a risk that the customer(s) may exceed any possible limitation of their system when any limitation is present.

icanfly
No disrespect, but I don't think you fully understand how the WKM works!!
The WKM itself limits the angle to 45 degress. To exceed this it must be in manual mode, then there is no limit.
This pilot did not test the WKM to it's limits...no where near it! as far as I can see it was just plain pilot error.
DJI have sold thousands of WKM units. One or two videos like this does not mean DJI needs to take urgent action with the product.

3DManA1, the gun on my hip is for my own personal protection, similar to the fire extinguishers in my shop. I hope to not have to use it, but like with a Fire Extinguisher, I have before and I am trained and capable...

While it is certainly possible that you have a defective DJI unit, my previous post was to highlight that there ARE other possibilities as to the difficulties you have been having.

I cannot excuse the difficulties you have had trying to communicate with DJI or their dealers, but if my own experience is any indication, spending a LOT of time on the phone and on the many different forums with customers of my own small company, it would be nigh IMPOSSIBLE to talk with everyone on the phone on the scale of the units that DJI have sold around the world.

I also must reiterate, that with the number of units that I have installed, setup, and tested, IF there were an inherent problem with the DJI unit itself, I would have seen it by now, and I would be the first to decry it. Again, not saying that you're individual unit may not have a problem, but you should also be considering other possibilities, looking at ALL aspects of your aircraft, radio setup, outside factors.

Chris D. Bergen

Colin,
Wow...here we are. I'm not a writer or typer so this way of communication is painful.

The DJI Wookong-M is advertised as a commercial professional multi-rotor product. Customers buying this product are probably intending to use it for aerial photography. This was our intent.

The S-800 and Wookong-M is their flagship multi-rotor machine advertised for this porpoise. After six flights the S-800 locked out and crashed. The S-800 is totaled and the Wookong-M caused the crash. Colin you admit that the system has flaws yet can't except the fact the system caused our problem. I realize how busy you must be developing all the DJI products and I feel sorry for your lot on life having to deal with all the customer complaints yet you advertise as being the main USA distributor. With all the sales you have to expect problems and be able to handle customer service.
Not taking the the time to call us after your system caused a three thousand dollar crash is not except able. I also feel you wasted our time and money having us send you the unit to test. More than a Month has gone by sense the crash and you are still are in possession of our machine yet haven't done anything but look at the video. You won't call me or give me any time to explain in detail what happened. Mark and I have requested a call and you haven't called. I guess the buck doesn't stop at your desk as you seem to need others to hold you your hand with a conference call. Mark, giant model products and I will be happy to conference call you any time. But then you know that as I have been requesting this for a month.

I've been flying R/C helicopters for over fifteen years and have been a helicopter rep. for ten years. I spend most of my weekends going to fun flys or helping people with helicopter set-up and 3D flight. I train people to fly 3D using a buddy box. One of the important things to reconize when buddy boxing is pilot error or dumb stick and mechanical problems and electronics problems. This is very hard to distinguish unless the radio sticks are in your hands. I feel that you don't have a clue when the S-800 went into lockout during the video you used to determine the cause of the crash.
Our system needs to be tested. Yet you don't even have time for a thirty minute phone call.

Thunderbirds Rock and Roar

Frustrated DJI consumer

Over a month and still no call and yet they still have our S-800 and radio equipment.

When I buy commercial grade equipment I expect more. If I were to buy a commercial lawn mower I would expect great service and a sturdier than non-commercial mower. If the mower broke down within the first week the problem would be corrected. The mower fixed and I'd be on my way. If I tried to use a non-commercial mower to due a commercial job and it broke I could expect my warranty not to cover the problem. This seems to be reasonable. DJI sales their product as commercial grade yet contradicts them selfs saying the system is for hobby grade work. Colin has told me in the past that he is only interested in the more serious customers that are going to spend ten thousand dollars or more for commercial type rig other than that Empire Hobby is to handle the hobby grade equipment. I guess our three thousand dollar problem is of no interest to Colin self proclaimed CEO North American DJI Innovations other than to get involved to Deni our claim after Empire Hobbies said our S-800 would be replaced.

If my Livelihood depended on a camera ship that functioned as advertised and that system was supposedly the best DJI had to offer and the thing wouldn't and couldn't even compleat Six flights and then on top of all that the only person that you can go to denies all responsibility, even when they admit to having multi able problems, then the business would just fold.

Colin, we still haven't heard from you. Are you alive???

I think snakes hibernate in the winter. Dose any one know the temperature in Austin.

Another week no call

Still no call.

Thunderbirds Rock and Roar

Professionalism

I think I will be sorry for speaking up but somehow i couldn't resist.

I understand you are mad and the fact is no one can tell if it is justified or not. I doubt it can/will ever be decided. But here are some thoughts I think DO run true.

1.Less is more. The more complicated something is, the more that can go wrong.
2.Too many variables means no controlled experiment. No control...no accurate conclusion.
3.Because someone sez a device is "professional" or "commercial" grade does not make it so. Besides, these words are sales words and are really vague and meaningless. I always thought that a a "professional' is just someone that got paid for a service.
4.Even professional equipment does not guarantee professional results.
5.No man is an island. If you are expecting to be a dealer or AP guy etc, you will need insurance, an attorney, an accountant, and more. When do you need them? Probably before you make your first purchase.
6.Saying is one thing. Writing is another. Try saying first but get to writing asap. The spoken word is harder to prove.
7.Theft is theft. If someone is holding your goods without your permission, you have cause for action. If the equipment was bought by someone else, you have nothing to talk about here or elsewhere.
8.Many good cases become better counter-cases depending upon how we handle ourselves. A thief of $3000 can become income loss due to defamation worth much much more. Say nothing. Write only what you can prove.
9.Compromise is an art few know how to use.
10. You deal with the person you bought something from. You can CC others but your complaint is simple. Don't involve their supplier or his brother in law (unless his brother in law is his attorney).
11.If you found out you have terminal cancer tomorrow, how important would this be? Well, that is how important it really is.
12.We think money is so valuable when TIME is our only real commodity. ie. Stop wasting time.

Chris D. Bergen

S800

Hey Doc. Good to hear from you as always. Didn't know you followed this forum. Ha.

3Dguy. I believe Chris is on to the answer. He knows a little bit about those things.

Your video shows jello, vibrations and a bad noise from the beginning of the startup and continues to the end. Just before the mishap, you did an especially hard banked turn followed by a steep dive (for a big multi). Whatever was causing the symptoms gave out. One side went out and the thing flew like a lopsided frisbee to the ground. I think the controller did it's best to compensate. Afterall, it didn't flip. One of you mentioned in the video the possiblility of a lost or broken blade. Lockout? Still a possibility but not one of the known weak points of the controller. Lockout would more likely be the fault of the builder in this case. As I said, no one will know for sure. But Chris is still right.

I have an S800. I don't fly it like a Pitts or a Gee Bee. Ask Dr. Tim how he flies his big Lama's and scalers. With multi's, the 550 and smaller is better suited for quick manuveurs and scatting around (and crashing) but they won;t have the stability of a bigger air frame. You kinda "over-flew" the S800 in some pretty gusty winds. And carbon fiber blades have good properties. Holding up to stress once there's a crack in the mold isn't one of them. All it takes is a close encounter while moving it from the car (or semi) to the field. Happens to the best of us and that's what keeps us so humble (and broke).

Didn't mean to bust your stones. Whoever's name is on the invoice should consider negotiating a compromise direct with the dealer...not manufacturer. If you can get half of your loss in cash or prizes, consider yourself (and the dealer) lucky dogs.